Could you try parted magic? It has always worked for me.
Awesome sig picture does not work
Brick Prevention- Things you should never do | Ignoring advice and bricking | Be a jedi, donate
Guide: Softmod ANY wii | How to post a system check | Loading and Playing Wii Backup Games from USB HDD (softmod only)
System Menu X (IOS150, E) | HBC 1.08 (IOS58) | bootmii/boot2v4 | priiloader 0.7 | cIOSX rev21d2x_v6 (main base IOS 57) | cIOS 223 (IOS 37 + 38 merged) | USB Loader GX 2.2